Support more type arguments in generic instantiation

Comments

Support more type arguments in generic instantiation
The real solution requires more work, so this is to buy us some time.
Change-Id: I033a77d05c0ca7658475d1fe59760ce4e5919f7e
Reviewed-on: https://dart-review.googlesource.com/65541
Reviewed-by: Sigmund Cherem <sigmund@google.com>